Number of persons employed by the Entity

No definition available.

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- Definition

Developers, builders, governmental agencies and municipalities will provide the entity with cash, or in some cases property, to extend its services to their properties. Nonrefundable contributions are recorded as contributions in aid of construction ("CIAC").

+ References

No definition available.

+ Details

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- Definition

Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(k)(1))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph a

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph k

-Subparagraph 1

-Article 4

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Related Parties

-URI http://asc.fasb.org/extlink&oid=16382449

+ Details

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- Definition

The distributions of earnings to an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

+ Details

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- Definition

The cash inflow from parent as a source of financing that is recorded as additional paid in capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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- Definition

Receivables to be collected from (obligations owed to) related parties, net as of the balance sheet date where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth.

+ References

+ Details

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- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Balance Type:	debit
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- Details

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- Definition

Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.

+ References

No definition available.

+ Details

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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- Details

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- Details

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Transactions with Major Customers and Affiliates (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014 employee	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2015
Related Party Transaction [Line Items]
Advances to affiliate	$ 135,054,000	$ 119,168,000
Related party transaction, rate	0.01%us-gaap_RelatedPartyTransactionRate
Entity number of employees	0dei_EntityNumberOfEmployees
Related party transaction, expenses from transactions with related party	102,400,000	106,700,000	113,000,000
Cash distributions to parent	234,000,000	91,000,000	137,500,000
Contributions from parent	0	13,300,000	8,630,000
Puget Sound Energy, Inc. [Member]
Revenue, Major Customer [Line Items]
Operating revenues	113,398,000	110,111,000	100,799,000
Northwest Natural Gas Company [Member]
Revenue, Major Customer [Line Items]
Operating revenues	50,631,000	51,085,000	42,297,000
Williams Field Services [Member]
Related Party Transaction [Line Items]
Reimbursable costs	27,300,000	89,800,000
Related party transaction, due from (to) related party	500,000	38,600,000
Williams Partners L.P. [Member]
Related Party Transaction [Line Items]
Advances to affiliate	135,100,000	119,200,000
Subsequent Event [Member]
Related Party Transaction [Line Items]
Cash distributions to parent				$ 58,000,000